Seperate Beast to two folders BEAST and Beast2

[fizwit]

BEAST and Beast2 are two separate projects in active development. The original BEAST project is an acronym for Bayesian Evolutionary Analysis Sampling Trees and should be capitalized.

Beast2 is a fork and takes a different approach. Its project page uses Beast2 for the project name.

The researchers at my site are very specific about the name and actively use both projects.
Using the one name Beast is hard to follow. The latest version of BEAST is 10.x, and Beast2 is only 2.7.7. Let's hope that BEAST does not add the X to its name, which is part of a very bad trend of calling things 'X'.

mkdir Beast2
cd Beast2
mv ../Beast/Beast-2* . 
# start using Beast2-2.7.7 

Put my PR for Beast-10.x into Beast.